17) $$\frac{\sqrt{16a^9} \cdot \sqrt{4b^3}}{\sqrt{a^5b^3}} = \frac{\sqrt{16a^9 \cdot 4b^3}}{\sqrt{a^5b^3}} = \sqrt{\frac{16a^9 \cdot 4b^3}{a^5b^3}} = \sqrt{16 \cdot 4 \cdot a^{9-5} \cdot b^{3-3}} = \sqrt{64a^4} = \sqrt{64} \cdot \sqrt{a^4} = 8a^2$$
при a = 9 и b = 11
$$8 \cdot 9^2 = 8 \cdot 81 = 648$$
Ответ: 648